A tomography apparatus controls the motion range of an X-ray apparatus or two-dimensional detector in accordance with an imaging region. Japanese Patent Application Laid-Open No. 2004-041702 (PLT1) and International Patent Application Publication WO/2007/100105 (PLT2) are related to such a tomography apparatus. PLT1 discloses a radiographic apparatus that radiographs an object with radiation from a movable radiation source. The radiographic apparatus detects a radiographic image of an object supported by a support portion by using a detection unit. At this time, based on the information of the position of the radiation source and an imaging target region of an object, a control unit controls the movement of at least one of the detection unit and the support portion so as to detect a projection image of the imaging target region.
A tomography apparatus designed to radiograph an object with radiation from a radiation source controls each of the electron sources of the radiation source, which are distributed two-dimensionally, to generate multi X-ray beams, and detects a radiographic image of the object by using a detector (see PLT2). Using such multi X-ray beams can perform tomography without moving both the radiation source and the detector.